Multiple Unmanned Aerial Vehicles Deployment and User Pairing for
Non-Orthogonal Multiple Access Schemes
Abstract
Non-orthogonal multiple access (NOMA) significantly improves the
connectivity opportunities and enhances the spectrum efficiency (SE) in
the fifth generation and beyond (B5G) wireless communications.
Meanwhile, emerging B5G services demand of higher SE in the NOMA based
wireless communications. However, traditional ground-to-ground (G2G)
communications are hard to satisfy these demands, especially for the
cellular uplinks. To solve these challenges, this paper proposes a
multiple unmanned aerial vehicles (UAVs) aided uplink NOMA method. In
detail, multiple hovering UAVs relay data for a part of ground users
(GUs) and share the sub-channels with the left GUs that communicate with
the base station (BS) directly. Furthermore, this paper proposes a
K-means clustering based UAV deployment and location based user pairing
scheme to optimize the transceiver association for the multiple UAVs
aided NOMA uplinks. Finally, a sum power minimization based resource
allocation problem is formulated with the lowest quality of service
(QoS) constraints. We solve it with the message-passing algorithm and
evaluate the superior performances of the proposed scheduling and paring
schemes on SE and energy efficiency (EE). Extensive experiments are
conducted to compare the performances of the proposed schemes with those
of the single UAV aided NOMA uplinks, G2G based NOMA uplinks, and the
proposed multiple UAVs aided uplinks with a random UAV deployment.
Simulation results demonstrate that the proposed multiple UAVs
deployment and user pairing based NOMA scheme significantly improves the
EE and the SE of the cellular uplinks at the cost of only a little
relaying power consumption of the UAVs.